#ifdef TCL_MEM_DEBUG

/*
 * One of the following structures is allocated each time the
 * "memory tag" command is invoked, to hold the current tag.
 */

typedef struct {
    size_t refCount;		/* Number of mem_headers referencing this
				 * tag. */
    char string[TCLFLEXARRAY];	/* Actual size of string will be as large as
				 * needed for actual tag. This must be the
				 * last field in the structure. */
} MemTag;

				 * to detect underruns. */
    char body[TCLFLEXARRAY];	/* First byte of client's space. Actual size
				 * of this field will be larger than one. */
};

static struct mem_header *allocHead = NULL;  /* List of allocated structures */

#define GUARD_VALUE  0x61

/*
 * The following macro determines the amount of guard space *above* each chunk
 * of memory.
 */

#define HIGH_GUARD_SIZE 8

/*
 * The following macro computes the offset of the "body" field within
 * mem_header. It is used to get back to the header pointer from the body
 * pointer that's used by clients.
 */

#define BODY_OFFSET \
	((size_t) (&((struct mem_header *) 0)->body))

static size_t total_mallocs = 0;
static size_t total_frees = 0;
static size_t current_bytes_malloced = 0;
static size_t maximum_bytes_malloced = 0;
static size_t current_malloc_packets = 0;
static size_t  maximum_malloc_packets = 0;
static size_t break_on_malloc = 0;
static size_t trace_on_at_malloc = 0;
static int alloc_tracing = FALSE;
static int init_malloced_bodies = TRUE;
#ifdef MEM_VALIDATE
static int validate_memory = TRUE;
#else
static int validate_memory = FALSE;
#endif

{
    char buf[1024];

    if (clientData == NULL) {
        return 0;
    }
    sprintf(buf,
	    "total mallocs             %10" TCL_Z_MODIFIER "u\n"
	    "total frees               %10" TCL_Z_MODIFIER "u\n"
	    "current packets allocated %10" TCL_Z_MODIFIER "u\n"
	    "current bytes allocated   %10" TCL_Z_MODIFIER "u\n"
	    "maximum packets allocated %10" TCL_Z_MODIFIER "u\n"
	    "maximum bytes allocated   %10" TCL_Z_MODIFIER "u\n",
	    total_mallocs,
	    total_frees,
	    current_malloc_packets,

    for (idx = 0; idx < LOW_GUARD_SIZE; idx++) {
	byte = *(memHeaderP->low_guard + idx);
	if (byte != GUARD_VALUE) {
	    guard_failed = TRUE;
	    fflush(stdout);
	    byte &= 0xFF;
	    fprintf(stderr, "low guard byte %" TCL_Z_MODIFIER "u is 0x%x  \t%c\n", idx, byte,
		    (isprint(UCHAR(byte)) ? byte : ' ')); /* INTL: bytes */
	}
    }
    if (guard_failed) {
	TclDumpMemoryInfo(stderr, 0);
	fprintf(stderr, "low guard failed at %p, %s %d\n",
		memHeaderP->body, file, line);
	fflush(stderr);			/* In case name pointer is bad. */
	fprintf(stderr, "%" TCL_Z_MODIFIER "u bytes allocated at (%s %d)\n", memHeaderP->length,
		memHeaderP->file, memHeaderP->line);
	Tcl_Panic("Memory validation failure");
    }

    hiPtr = (unsigned char *)memHeaderP->body + memHeaderP->length;
    for (idx = 0; idx < HIGH_GUARD_SIZE; idx++) {
	byte = *(hiPtr + idx);
	if (byte != GUARD_VALUE) {
	    guard_failed = TRUE;
	    fflush(stdout);
	    byte &= 0xFF;
	    fprintf(stderr, "hi guard byte %" TCL_Z_MODIFIER "u is 0x%x  \t%c\n", idx, byte,
		    (isprint(UCHAR(byte)) ? byte : ' ')); /* INTL: bytes */
	}
    }

    if (guard_failed) {
	TclDumpMemoryInfo(stderr, 0);
	fprintf(stderr, "high guard failed at %p, %s %d\n",

	allocHead->blink = result;
    }
    allocHead = result;

    total_mallocs++;
    if (trace_on_at_malloc && (total_mallocs >= trace_on_at_malloc)) {
	(void) fflush(stdout);
	fprintf(stderr, "reached malloc trace enable point (%" TCL_Z_MODIFIER "u)\n",
		total_mallocs);
	fflush(stderr);
	alloc_tracing = TRUE;
	trace_on_at_malloc = 0;
    }

    if (alloc_tracing) {
	fprintf(stderr,"ckalloc %p %u %s %d\n",
		result->body, size, file, line);
    }

    if (break_on_malloc && (total_mallocs >= break_on_malloc)) {
	break_on_malloc = 0;
	(void) fflush(stdout);
	Tcl_Panic("reached malloc break limit (%" TCL_Z_MODIFIER "u)", total_mallocs);
    }

    current_malloc_packets++;
    if (current_malloc_packets > maximum_malloc_packets) {
	maximum_malloc_packets = current_malloc_packets;
    }
    current_bytes_malloced += size;

	allocHead->blink = result;
    }
    allocHead = result;

    total_mallocs++;
    if (trace_on_at_malloc && (total_mallocs >= trace_on_at_malloc)) {
	(void) fflush(stdout);
	fprintf(stderr, "reached malloc trace enable point (%" TCL_Z_MODIFIER "u)\n",
		total_mallocs);
	fflush(stderr);
	alloc_tracing = TRUE;
	trace_on_at_malloc = 0;
    }

    if (alloc_tracing) {
	fprintf(stderr,"ckalloc %p %u %s %d\n",
		result->body, size, file, line);
    }

    if (break_on_malloc && (total_mallocs >= break_on_malloc)) {
	break_on_malloc = 0;
	(void) fflush(stdout);
	Tcl_Panic("reached malloc break limit (%" TCL_Z_MODIFIER "u)", total_mallocs);
    }

    current_malloc_packets++;
    if (current_malloc_packets > maximum_malloc_packets) {
	maximum_malloc_packets = current_malloc_packets;
    }
    current_bytes_malloced += size;

    memp = (struct mem_header *) (((size_t) ptr) - BODY_OFFSET);

    copySize = size;
    if (copySize > memp->length) {
	copySize = memp->length;
    }
    newPtr = (char *)Tcl_DbCkalloc(size, file, line);
    memcpy(newPtr, ptr, copySize);
    Tcl_DbCkfree(ptr, file, line);
    return newPtr;
}

char *
Tcl_AttemptDbCkrealloc(

    memp = (struct mem_header *) (((size_t) ptr) - BODY_OFFSET);

    copySize = size;
    if (copySize > memp->length) {
	copySize = memp->length;
    }
    newPtr = (char *)Tcl_AttemptDbCkalloc(size, file, line);
    if (newPtr == NULL) {
	return NULL;
    }
    memcpy(newPtr, ptr, copySize);
    Tcl_DbCkfree(ptr, file, line);
    return newPtr;
}

	    Tcl_SetObjResult(interp, Tcl_ObjPrintf("error accessing %s: %s",
                    TclGetString(objv[2]), Tcl_PosixError(interp)));
	    return TCL_ERROR;
	}
	return TCL_OK;
    }
    if (strcmp(TclGetString(objv[1]),"break_on_malloc") == 0) {
	Tcl_WideInt value;
	if (objc != 3) {
	    goto argError;
	}
	if (Tcl_GetWideIntFromObj(interp, objv[2], &value) != TCL_OK) {
	    return TCL_ERROR;
	}
	break_on_malloc = value;
	return TCL_OK;
    }
    if (strcmp(TclGetString(objv[1]),"info") == 0) {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"%-25s %10" TCL_Z_MODIFIER "u\n%-25s %10" TCL_Z_MODIFIER "u\n%-25s %10" TCL_Z_MODIFIER "u\n%-25s %10" TCL_Z_MODIFIER "u\n%-25s %10" TCL_Z_MODIFIER "u\n%-25s %10" TCL_Z_MODIFIER "u\n",
		"total mallocs", total_mallocs, "total frees", total_frees,
		"current packets allocated", current_malloc_packets,
		"current bytes allocated", current_bytes_malloced,
		"maximum packets allocated", maximum_malloc_packets,
		"maximum bytes allocated", maximum_bytes_malloced));
	return TCL_OK;
    }

	    goto bad_suboption;
	}
	alloc_tracing = (strcmp(TclGetString(objv[2]),"on") == 0);
	return TCL_OK;
    }

    if (strcmp(TclGetString(objv[1]),"trace_on_at_malloc") == 0) {
	Tcl_WideInt value;
	if (objc != 3) {
	    goto argError;
	}
	if (Tcl_GetWideIntFromObj(interp, objv[2], &value) != TCL_OK) {
	    return TCL_ERROR;
	}
	trace_on_at_malloc = value;
	return TCL_OK;
    }
    if (strcmp(TclGetString(objv[1]),"validate") == 0) {
	if (objc != 3) {